The most common type of stomach (gastric) cancer is an adenocarcinoma (from cells that form any kind of glands). Gastric cancers are far less common than a century ago, probably because we now use refrigeration rather than older ways to preserve food, such as salting and smoking. Cancers arising near the small bowel have continued to decrease, but cancers closer to the esophagus have been increasing, especially in patients under 40.

Being infected with H. pylori bacteria increases the risk of stomach cancer, particularly in Asian Americans. A diet high in salted and smoked foods and low in fruits and vegetables, as well as smoking and genetic factors, increase the risk of developing stomach cancer. Like most cancers, stomach cancer increases with age.

The patient's prognosis depends on how deeply the cancer invades into the wall of the stomach and whether it extends into lymph nodes, which define the stage (from I to IV). Tumor grade, which increases from I-III as it becomes more abnormal-looking under the microscope, also affects the patientís outcome.

Treating Gastric Cancer

Depending on their cancer type and stage, gastric patients may be treated with surgery, radiation therapy, chemotherapy or a combination. Early gastric cancer (Stage I) may be successfully treated with surgery alone. Most patients with stage II-IV gastric cancer are best treated with combinations of surgery, radiation and chemotherapy. Therefore, a patient diagnosed with stomach cancer should be treated where these treatments are offered by experienced cancer doctors used to working as a team.

Surgery–Surgery to remove a tumor offers the best chance for long-term control of all types of gastric cancer. If we believe we can completely remove a tumor by surgery, it is called resectable. However, even completely removed gastric cancers are at high risk of returning (recurring). Recurrence can occur when a microscopic amount of the cancer spreads prior to the surgery. Therefore additional treatments are often given along with gastric cancer surgery.

Neoadjuvant Therapy–Cancer treatment given before the surgery is called neoadjuvant therapy. It generally involves chemotherapy alone or chemotherapy with radiation. Neoadjuvant treatment can reduce the size of the tumor so it is more easily removed during surgery. It can also reduce the chance of cancer recurrence.

Adjuvant Therapy–Adjuvant treatments are given after all the cancer we can see has been removed by surgery or treated with radiation. The aim of adjuvant therapy is to kill cancer cells that have spread (and we cannot see) while their numbers are small and treatment is more effective, to prevent tumor recurrence.

Chemotherapy–Chemotherapy is cancer treatment that uses drugs to kill cancer cells by damaging their ability to grow and divide. We call drug treatments systemic therapy, because they go everywhere in the body to attack all cells, including cancer cells and healthy cells. Chemotherapy often prevents gastric tumors from growing and sometimes shrinks them.

Chemotherapy drugs are usually administered through a vein into the bloodstream (intravenously), but some can be given by mouth (orally). Usually, patients receive chemotherapy as an outpatient treatment at a hospital, clinic or doctorís office. The time needed for each treatment session depends on the type of chemotherapy.

Radiation Therapy–Radiation therapy uses high-energy X-rays or other types of high energy waves to kill cancer cells or prevent them from growing. Radiation treatment often stops stomach cancers from growing and sometimes shrinks them. Since radiation therapy only affects the cancer cells in the area where it is aimed, it is considered a local treatment, like surgery.

Adjuvant Chemotherapy or Radiation Therapy–Adjuvant treatments are given after all the cancer we can see has been removed by surgery or treated with radiation. Often, adjuvant chemotherapy or radiation therapy is given after gastric cancer surgery to reduce the risk of cancer recurrence, or reappearance. Recurrence can occur when a microscopic amount of the cancer spreads prior to the surgery. The aim of adjuvant therapy is to kill microscopic cancer cells while their numbers are small and these treatments are more effective, thereby preventing recurrence of a tumor.

The graph below shows the overall survival for all patients under age 80 diagnosed with gastric cancer by stage. These results compare favorably with the results of gastric patients in treatment trials, indicating the ability of our multidisciplinary teams to provide complex, integrated treatment programs.

Clinical Trials

Gastric cancer clinical trials, or research studies, are necessary to determine whether new treatments developed in the laboratory are beneficial to people with gastric cancer. The Food and Drug Administration (FDA) reviews and analyzes data from successful clinical trials to determine whether to approve an experimental treatment to treat a specific disease or disorder, such as gastric cancer.

Clinical trials are the only way that researchers can get the information to find effective new treatments for gastric cancer. Currently, only about 3 percent of adult cancer patients enroll in a clinical trial, which slows progress in finding better treatments. Many patients are not aware that taking part in a research study is an option.

It is important for you to know that inactive treatments, or placebos, are never used in place of effective cancer treatments in clinical trials. Participants in a cancer clinical trial will receive either the standard treatment or the new treatment.

Clinical trials for gastric cancer may be carried out using completely new treatments or whether treatments that work for other cancers are effective against gastric cancer.